The 22-time grand slam winner is skipping Wuhan -- which begins next week -- and Beijing with a shoulder injury but said she hopes to come back in time for the season-ending WTA Finals in Singapore in late October.
"I am disappointed that I will not be able to compete at the Dongfeng Motor Wuhan Open or the China Open due to continuing issues with my right shoulder," the American said in a statement posted on the WTA's website Friday.
"I have been practicing and playing but my shoulder is still not fit for tournament play. I wish the tournaments great success and I'm sure the fans will enjoy some great tennis. I am focused on getting ready to compete at the WTA Finals in Singapore."
Playing tournaments unhealthy
The shoulder issue has affected Williams for the past couple of months and she also sustained a knee injury at the US Open, where the soon-to-be 35-year-old was upset by Karolina Pliskova in the semifinals.
Williams' 186-week reign at No. 1 in the rankings came to an end after Flushing Meadows, replaced by US Open winner Angelique Kerber of Germany.
"I'm tired of playing tournaments unhealthy and taking losses that I would never lose," Williams told CNN on Monday at the unveiling of her French coach Patrick Mouratoglou's new academy near Nice.
"I definitely want to make sure I'm healthy and playing at my best or at least 80% healthy or 70% healthy -- that way I can be able to play at a higher level."
Target of 30 majors
Williams decided to shut down her season in 2015 after the US Open, citing injuries and a tough loss to Roberta Vinci in the semifinals of the Flushing Meadows tournament.
Vinci downed Williams to end her bid to become the first player since Steffi Graf in 1988 to achieve a calendar-year grand slam.
Williams won one grand slam title in 2016 — losing two finals — to match Graf for the Open Era record and trails only Margaret Court's 24 on the all-time grand slam list.
Mouratoglou, who called it a bad season for Williams despite her victory at Wimbledon, set a target of 30 majors for the now world No. 2.
"Why not set up a record that will never be beaten in history?" he told CNN on Monday. "I think she can do it."